Gaseous electric discharge lamp device



Nov. 21, 1.933.

H1. EWE$T ET AL GASEOUS ELECTRIC DISCHARGE LAMP DEVIG'E Filed June 6,1955 2 Shams-Sheet l 12my111121 912mmwm/imww INVENTORS BY g ATTORN EYNov. 21, 1933. H, EWEST Er AL WBW GASEOUS ELECTRIC DISCHARGE LAMP DEVICEFiled. June 6, 1955 2 smats shem r2 INVENTORS 25m 69M M 9/" BY WM ATTORNEY Patented Nov. 21, 1933 GASEOUS ELECTRIC DEVI JSCHARGE LAMP HansEwost, Berlin-Lichterfelde, and Kurt Wiegand, Berlin-Tempelhof, andMartin Reger, Berlin, Germany, assignors to General Electric Company, acorporation of New York Application June 6, 1933, Serial No. 674,519 andin Germany June 18, 1932 5 Claims.

The present invention relates to gaseous electric discharge lamp devicesgenerally and more particularly the invention relates to improvements inmethods and means for starting such devices into operation.

The starting of gaseous electric discharge devices is facilitated bymounting an electrically conducting, straight wire along thegaseouselectrio discharge path in the container of the device. The wireis usually electrically connected to one of the electrodes of the deviceand when the starting voltage is applied across the electrodes of thedevice a glow discharge takes place between said wire and the electrodeopposite that to which said wire is connected. The glow dischargeextends along the length of the wire so that a heavy ionization of thedischarge path takes place which facilitates the starting of the maindischarge in the device. While this method of and means for starting issuccessful and effective the wire is frequently subjected to a heavyelectronic and ionic bombardment and a spot thereon is raised to itsmelting temperature by the main discharge during the operation of thedevice. Under these conditions the wire is apt to break at the heatedpart to reduce the efiectiveness thereof for starting purposes. Theparticles knocked off the wire by the electronic and ionic bombardmentform deposits of light opaque material on the walls of the container ofthe device which reduce the efliciency and the useful operating life ofthe device.

The object of the present invention is to provide a gaseous electricdischarge device of the above type in which the above difficulties areavoided. Another object of the invention is to provide a gaseouselectric discharge device in which starting is quicker and more positivethan those of the same type now known in the art. A further object ofthe invention is to provide a gaseous electric discharge device adaptedto start and operate on 110 or 220 volt current sources of commerce andwhich has a long useful operating life. Still further objects andadvantages attaching to the device and to its use and operation will beapparent to those skilled in the art from the following particulardescription and from the appended claims.

.The invention attains its objects by providing an electricallyconducting coiled wire along the discharge path between the maindischarge supporting electrodes, out of contact with said electrodes,terminating adjacent said electrodes and covered with an insulatingmaterial between the exposed end parts thereof. The insulating materialprotects all parts of the wire except the end parts thereof from anelectronic and ionic bombardment during the operation of the device.When the starting voltage is applied to the electrodes of the device anauxiliary discharge develops between each of the main electrodes and theend part of the wire adjacent thereto. The intensity of the auxiliarydischarges and the temperature of the end parts of said wire arecontrolled, among other factors, by the resistance of said wire. Asthese end parts of the wire are located adjacent the main dischargesupporting electrodes any sputtered material therefrom deposits on thoseparts of the container wall adjacent the electrodes and as these partsare not used for light transmission the light opaque deposits ofsputtered material thereon do not reduce the efliciency of the device.The resistance of the coiled wire is suflicient to prevent thedevelopment of an arc discharge between the exposed wire ends and themain electrodes and to prevent said end parts from reaching the meltingtemperature during the starting and operation of the device. We havediscovered that a condenser discharge takes place between the wire andthe main discharge supporting electrodes and that the intensity of saidcondenser discharge increases directly as the length of the wire. In thepreferred embodiments of our invention the wire is a convolutejand ahelical shaped wire is preferred. The condenser discharge and theauxiliary discharges which take place along the discharge path duringthe starting period cause a heavy ionization of the gas in said path tofacilitate the starting of the main discharge in the device.

In the drawings accompanying and forming part of this specificationseveral embodiments of the invention are shown in which:

Fig. 1 is a side elevational view of one type of gaseous discharge lampdevice embodying the invention, the circuit therefor being shownschematically,

Fig. 2 is a sectional view along the line 2-2 of Fig. 1,

Fig. 3 is a detail view of another form of conductive element useful inthe invention,

Fig. 4 is a side elevational perspective view of another type of gaseouselectric discharge device 105 embodying the present invention,

Fig. 5 is a detail view of another form of insulated wire useful in theinvention, and

Fig. 6 is a similar view of still another form of insulated wire usefulin the present invention.

Like numbers denote like parts in all the figures.

Referring to Fig. 1 of the drawings the new and novel gaseous electricdischarge lamp device comprises a container 1 having a stem 2 at eitherend thereof. Inleads 3 and 4 for each of said electrodes 5 are sealedinto each of the stems 2. Said container 1 has a gaseous atmospheretherein comprising rare gas, common gas, mixtures of gases, metal vapor,or gas-vapor mixtures and is, for example, neon, or a mixture of argonand mercury vapor. The starting and operating mixtures of gases wellknown in the art are used in said container 1 where desired. Saidelectrode 5 comprises a heater filament, such as a tungsten filament,wrapped around a rod made of a sintered mixture of a metal having a highmelting point, and electron emitting material, such as a mixture oftungsten, barium oxide and strontium oxide. The tungsten filament isconnected across the current inleads 3 and 4. Each pair of said leads 3and 4 are connected to the secondary of a transformer 12 adapted tosupply the heater current for said electrodes 5. Said leads 4 are themain current leads for said electrodes 5 and each of said leads 4 isconnected to a terminal 16 of a commercial alternating current source ofor 220 volts. A choke coil 13 is connected into one of the leads 4 whichregulates the potential across said electrodes 5 after the device hasbeen started into operation. The primary of each of said heatertransformers 12 is connected in parallel with said lamp device 1 andbetween the choke coil 13 and the electrodes 5. The potential on saidtransformers 12 is thus less during the operation of the lamp device 1than during the starting period which prevents overloading of the heaterfilament of said electrode 5 during the operation of the lamp device 1.

An electrically conducting helically wound wire 8, enclosed in astraight glass insulating tube 9, is supported in said container 1 bytwo pairs of semi-circular spring members 10 attached to said glass tube9 and pressing against the inher wall of said container 1, as shown inFig. 2. The straight end parts 14 of said wire 8 are not enclosed insaid tube 9 and are located a distance from said electrodes 5 less thanthe striking distance of the potential applied across said electrodes 5.When a voltage of 110 or 220 volts is applied to the above describeddevice the electrodes 5 are quickly brought to an electron emittingtemperature by the heater current supplied by transformers 12.Simultaneously an auxiliary discharge takes place between each of theelectrodes 5 and the respective ends 14 of the wire 8 adjacent theretowhich assists in quickly heating each of said electrodes 5 to anelectron emitting temperature. A condenser discharge takes place betweenthat part of the wire 8 enclosed in said tube 9 and the electrodes 5.The intensity of the condenser discharge depends on the length of saidwire 8, and the intensity of the auxiliary discharge depends, amongother factors, upon the resistance of said wire 8. The resistance ofwire 8 is suflicient to prevent the end parts 14 thereof from reaching amelting temperature during the starting and operating periods of thedevice. The auxiliary discharges and the condenser discharge speed upthe electrons emitted by the heated electrodes 5 which increases theionization of the gas in the discharge path between said electrodes 5 tofacilitate the starting of the gaseous electric discharge between saidelectrodes 5. As said wire 8 is of helical shape and extends along thefull length of the discharge path between said electrodes 5 thecondenser discharge is an intense one and speeds up the electronsthroughout said discharge path which results in a heavy ionization ofthe gas in all parts of said path as well as at the ends thereof in theregion surrounding the auxiliary discharges between said electrodes 5and said end parts 14. This, of course, is very advantageous in startingsuch devices into operation.

The structure of the tube 9 and wire 8 illustrated in Fig. 3 is used inelectric discharge lamp devices of equal or greater length than those inwhich the wire 8 and tube 9 shown in Fig. 1 are used. In this structurethe helically wound wire 8 is divided into two parts of equal length andthe adjacent straight end parts 15 of said wire 8 project from the wallof the tube 9. Said end parts 15 are separated a slight distance fromeach other. The element consisting of tube 9 and wire 8 is mounted inthe container of a gaseous electric discharge lamp device as shown inFig. 1. When the starting voltage is applied across the terminals of thedevice an auxiliary, starting discharge of the same type as that betweeneach of the ends 14 and the electrode 5 adjacent thereto takes placebetween said end parts 15 in addition to the other discharges discussedin connection with Fig. 1. This of course results in a heavy ironizationof the gas throughout the length of the discharge path which facilitatesthe starting of the main discharge in the lamp device. It will beunderstood, of course, that the wire 8 is divided in more than two partsof equal length, when desired.

The embodiment of the invention illustrated in Fig. 4 is used inconjunction with the circuit described in connection with Fig. 1 andthis embodiment is similar in all respects to that illustrated in Fig. 1except that in this embodiment the ends of wire 8 are rods 6 made ofmaterial similar to the material in the rod of electrodes 5. The rods 6are supported by metal rods 7 sealed into the stems 2. Said rods 6, aswell as the electrodes 5, are heated to an electron emitting temperatureby radiation of heat from said electrodes 5 and by the auxiliarydischarge which takes place between each of the electrodes 5 and the rod6 adjacent thereto. The provision of two additional, prolific sources ofelectrons in the lamp device facilitates further the starting of themain discharge between said electrodes 5. In other respects the startingand operation of the device is the same as that described in connectionwith Fig. 1. It will beunderstood, of course, that an element similar tothat shown in Fig. 3 is used in the above described device, whendesired.

A helically wound glass tube 9 having a similarly wound wire 8 enclosedtherein is illustrated in Fig. 5. This tube 9 is more flexible than thatillustrated in Figs. 1 and 4 and is used in lamp devices similar tothose illustrated in Figs. 1 and 4 and in lamps having a curved tubularcontainer. Such a lamp device has, when desired. two parallel tubularlegs of equal length, electrodes sealed into one end 01' each of saidlegs and a curved portion connecting the ends of said legs opposite theelectrodes. Such a lamp device is of U-shape, the electrodes thereof areapproximately in the same plane and the tube 9 and wire 8 sourrounds thedischarge path between the electrodes.

Another flexible, insulating tube for said wire 8 is illustrated in Fig.6 of the drawings. In this case a number of overlap lns conically shaped150 beads 11, known in the art as fishspine beads, surround said wire 8.This type of flexible tube is used in curved or straight containerssimilar to those discussed in connection with Fig. 5.

It will be understood, of course, that the method and means describedabove is used in electric discharge devices wherein the gaseous electricdischarge between'the main discharge supporting electrode is a positivecolumn discharge of either the glow or arc type, when desired.

While we have shown and described and have pointed out in the annexedclaims certain novel features of the invention, it will be understoodthat various omissions, substitutions and changes in the forms anddetails of the device illustrated and in its,use and operation may bemade by those skilled in the art without departing from the broad spiritand scope of the invention, for example, said rods 6 are electricallyconnected to the electrode 5 adjacent thereto, when desired, and saidelectrodes 5 are, when desired, of the self-heating, mixed metal andoxide type lrnown in the art as Pirani electrodes.

What we claim as new and desire to secure by Letters Patent of theUnited States is:-

1. An electric discharge device comprising a container, electrodessealed therein, a gaseous atmosphere therein, a body of electricallyconducting material extending along the discharge path between saidelectrodes and terminating adjacent said electrodes and a covering ofinsulating material for the part of said body in-= termediate its endsto protect said part from an electronic and ionic bombardment during theoperation of the device.

2. An electric discharge device comprising a container, electrodessealed therein, a gaseous atmosphere therein, a convoluted body ofelectrically conducting material having a high resistance, extendingalong the discharge path between said electrodes and terminatingadjacent said electrodes and a covering of insulating material for thepart of said body intermediate its ends to protect said part from anelectronic and ionic bombardment during the operation of the device.

3. An electric discharge device comprising a container, electrodessealed therein, a gaseous atmosphere therein, two convoluted bodies ofelectrically conducting material extending along the discharge pathbetween said electrodes, one end of each of said bodies being adjacentone of said electrodes, the other end of each of said bodies beingadjacent the end of the other of said bodies, and a covering ofinsulating material for the part of said bodies intermediate the endsthereof to protect said part from an electronic and ionic bombardmentduring the operation of the device.

4. An electric discharge device comprising a container, electrodessealed therein, a gaseous atmosphere therein, a body of electricallyconducting material extending along the discharge path between saidelectrodes and terminating adjacent said electrodes, the end parts ofsaid body being of a material capable of emitting electrons when heated,and a covering of insu lating material for the part of said bodyintermediate its ends to protect said part from an electronic and ionicbombardment during the operation of the device.

5. An electric discharge device comprising a container, electrodessealed therein, a gaseous atmosphere therein, a convoluted body ofelectrically conducting material having a high resistance, extendingalong the discharge path between said electrodes and terminatingadjacent said electrodes, the end parts of said body being of a materialcapable of emitting electrons when heated and a covering of insulatingmaterial for the part of said body intermediate its ends to protect saidpart from an electronic and ionic bombardment during the operation ofthe device.

HANS EW'EST. KURT WJIEGAND. MARTIN REGER.

